This disclosure relates to a nanophosphor and a method for preparing a nanophosphor from metal hydroxy carbonate. The method is useful for the mass-production of a uniform particle-size nanophosphor with superior dispersibility and high-efficiency.
Luminescence is defined as a phenomenon in which a material absorbs external energy to emit visible light. In a broad sense, a material exhibiting this phenomenon is called a “phosphor”.
Reduction in the particle size of a nanophosphor results in variation in the energy level of emission and a reduction in afterglow time, thus causing a shift in the energy of peaks in photoluminescence spectra to a shorter wavelength.
Commercially available methods for preparing nanophosphors include spray pyrolysis, wet methods and solid phase methods. The spray pyrolysis method has advantages in that the uniformity and size of nanophosphor particles produced by spray pyrolysis are more readily controlled. However, this method has disadvantages in the occurrence of defects (e.g., pores) in the final phosphor particles that make it difficult to further improve the luminescence efficiency of phosphors prepared by spray pyrolysis. In addition, the method is impractical for mass-production due to high preparation costs.
Other approaches have been considered for the preparation of nanophosphors. However, commercially available methods have problems associated with particle dispersibility, particle size distribution, color purity and luminescence efficiency.